Flavour | Article about flavour by The Free Dictionary Flavour | Article about flavour by The Free Dictionary Related to flavour: Natural flavour flavour (US), flavor Physics a property of quarks that enables them to be differentiated into six types: up, down, strange, charm, bottom (or beauty), and top (or truth) flavour (jargon) (US: flavor) 1. Variety, type, kind. "DDT commands come in two flavors." "These lights come in two flavors, big red ones and small green ones." See vanilla . 2. The attribute that causes something to be flavourful. Usually used in the phrase "yields additional flavour". "This convention yields additional flavor by allowing one to print text either right-side-up or upside-down." See vanilla . This usage was certainly reinforced by the terminology of quantum chromodynamics, in which quarks (the constituents of, e.g. protons) come in six flavors (up, down, strange, charm, top, bottom) and three colours (red, blue, green), however, hackish use of "flavor" at MIT predated QCD. 3. The term for " class " (in the object-oriented sense) in the LISP Machine Flavors system.

Though the Flavors design has been superseded (notably by the Common LISP CLOS facility), the term "flavor" is still used as a general synonym for "class" by some Lisp hackers. subatomic particle - Quarks and antiquarks | physics | Britannica.com Quarks and antiquarks Walther Bothe The baryons and mesons are complex subatomic particles built from more-elementary objects, the quarks . Six types of quark, together with their corresponding antiquarks, are necessary to account for all the known hadrons. The six varieties, or “ flavours ,” of quark have acquired the names up, down, charm, strange, top, and bottom. The meaning of these somewhat unusual names is not important; they have arisen for a number of reasons. What is important is the way that the quarks contribute to matter at different levels and the properties that they bear. The quarks are unusual in that they carry electric charges that are smaller in magnitude than e, the size of the charge of the electron (1.6 × 10−19 coulomb ).

This is necessary if quarks are to combine together to give the correct electric charges for the observed particles, usually 0, +e, or −e. Only two types of quark are necessary to build protons and neutrons , the constituents of atomic nuclei. These are the up quark , with a charge of +2/3e, and the down quark , which has a charge of −1/3e. The proton consists of two up quarks and one down quark, which gives it a total charge of +e. The neutron, on the other hand, is built from one up quark and two down quarks, so that it has a net charge of zero. The other properties of the up and down quarks also add together to give the measured values for the proton and neutron. For example, the quarks have spins of 1/2. In order to form a proton or a neutron, which also have spin 1/2, the quarks must align in such a way that two of the three spins cancel each other, leaving a net value of 1/2. Up and down quarks can also combine to form particles other than protons and neutrons.

For example, the spins of the three quarks can be arranged so that they do not cancel. In this case they form short-lived resonance states, which have been given the name delta , or Δ. The deltas have spins of 3/2, and the up and down quarks combine in four possible configurations—uuu, uud, udd, and ddd—where u and d stand for up and down. The charges of these Δ states are +2e, +e, 0, and −e, respectively. Similar Topics monatomic gas The up and down quarks can also combine with their antiquarks to form mesons . The pi-meson , or pion, which is the lightest meson and an important component of cosmic rays , exists in three forms: with charge e (or 1), with charge 0, and with charge −e (or −1). In the positive state an up quark combines with a down antiquark; a down quark together with an up antiquark compose the negative pion; and the neutral pion is a quantum mechanical mixture of two states—uu and dd, where the bar over the top of the letter indicates the antiquark.

Up and down are the lightest varieties of quarks. Somewhat heavier are a second pair of quarks, charm (c) and strange (s), with charges of +2/3e and −1/3e, respectively. A third, still heavier pair of quarks consists of top (or truth, t) and bottom (or beauty, b), again with charges of +2/3e and −1/3e, respectively. These heavier quarks and their antiquarks combine with up and down quarks and with each other to produce a range of hadrons , each of which is heavier than the basic proton and pion, which represent the lightest varieties of baryon and meson, respectively. For example, the particle called lambda (Λ) is a baryon built from u, d, and s quarks; thus, it is like the neutron but with a d quark replaced by an s quark. The development of modern particle theory Space Objects: Fact or Fiction Quantum electrodynamics: Describing the electromagnetic force The year of the birth of particle physics is often cited as 1932.

Near the beginning of that year James Chadwick , working in England at the Cavendish Laboratory in Cambridge , discovered the existence of the neutron . This discovery seemed to complete the picture of atomic structure that had begun with Ernest Rutherford’s work at the University of Manchester , England, in 1911, when it became apparent that almost all of the mass of an atom was concentrated in a nucleus. The elementary particles seemed firmly established as the proton , the neutron, and the electron . By the end of 1932, however, Carl Anderson in the United States had discovered the first antiparticle —the positron , or antielectron. Moreover, Patrick Blackett and Giuseppi Occhialini , working, like Chadwick, at the Cavendish Laboratory, had revealed how positrons and electrons are created in pairs when cosmic rays pass through dense matter. It was becoming apparent that the simple pictures provided by electrons, protons, and neutrons were incomplete and that a new theory was needed to explain fully the phenomena of subatomic particles. Britannica Stories Ringling Bros. Folds Its Tent The English physicist P.A.M.

Dirac had provided the foundations for such a theory in 1927 with his quantum theory of the electromagnetic field . Dirac’s theory treated the electromagnetic field as a “gas” of photons (the quanta of light), and it yielded a correct description of the absorption and emission of radiation by electrons in atoms. It was the first quantum field theory . A year later Dirac published his relativistic electron theory , which took correct account of Albert Einstein’s theory of special relativity . Dirac’s theory showed that the electron must have a spin quantum number of 1/2 and a magnetic moment. It also predicted the existence of the positron, although Dirac did not at first realize this and puzzled over what seemed like extra solutions to his equations. Only with Anderson’s discovery of the positron did the picture become clear: radiation , a photon , can produce electrons and positrons in pairs, provided the energy of the photon is greater than the total mass-energy of the two particles—that is, about 1 megaelectron volt (MeV; 106 eV). Dirac’s quantum field theory was a beginning, but it explained only one aspect of the electromagnetic interactions between radiation and matter.

During the following years other theorists began to extend Dirac’s ideas to form a comprehensive theory of quantum electrodynamics (QED) that would account fully for the interactions of charged particles not only with radiation but also with one another. One important step was to describe the electrons in terms of fields, in analogy to the electromagnetic field of the photons. This enabled theorists to describe everything in terms of quantum field theory. It also helped to cast light on Dirac’s positrons. Connect with Britannica Facebook Twitter YouTube Instagram Pinterest According to QED, a vacuum is filled with electron-positron fields. Real electron-positron pairs are created when energetic photons, represented by the electromagnetic field, interact with these fields. Virtual electron-positron pairs, however, can also exist for minute durations, as dictated by Heisenberg’s uncertainty principle , and this at first led to fundamental difficulties with QED. During the 1930s it became clear that, as it stood, QED gave the wrong answers for quite simple problems. For example, the theory said that the emission and reabsorption of the same photon would occur with an infinite probability.

This led in turn to infinities occurring in many situations; even the mass of a single electron was infinite according to QED because, on the timescales of the uncertainty principle, the electron could continuously emit and absorb virtual photons. It was not until the late 1940s that a number of theorists working independently resolved the problems with QED. Julian Schwinger and Richard Feynman in the United States and Tomonaga Shin’ichirō in Japan proved that they could rid the theory of its embarrassing infinities by a process known as renormalization . Basically, renormalization acknowledges all possible infinities and then allows the positive infinities to cancel the negative ones; the mass and charge of the electron, which are infinite in theory, are then defined to be their measured values. Once these steps have been taken, QED works beautifully. It is the most accurate quantum field theory scientists have at their disposal. In recognition of their achievement, Feynman, Schwinger, and Tomonaga were awarded the Nobel Prize for Physics in 1965; Dirac had been similarly honoured in 1933. The Particle Adventure | What is the world made of?

| The naming of quarks The Standard Model > What is the world made of? > The naming of quarks The naming of quarks The naming of quarks... ...began when, in 1964, Murray Gell-Mann and George Zweig suggested that hundreds of the particles known at the time could be explained as combinations of just three fundamental particles. Gell-Mann chose the name "quarks," pronounced "kworks," for these three particles, a nonsense word used by James Joyce in the novel Finnegan's Wake: "Three quarks for Muster Mark!" In order to make their calculations work, the quarks had to be assigned fractional electrical charges of 2/3 and -1/3. Such charges had never been observed before. Quarks are never observed by themselves, and so initially these quarks were regarded as mathematical fiction. Experiments have since convinced physicists that not only do quarks exist, but there are six of them, not three. How did quarks get their silly names? There are six flavors of quarks. "Flavors" just means different kinds. The two lightest are called up and down. The third quark is called strange.

It was named after the "strangely" long lifetime of the K particle, the first composite particle found to contain this quark. The fourth quark type, the charm quark, was named on a whim. It was discovered in 1974 almost simultaneously at both the Stanford Linear Accelerator Center (SLAC) and at Brookhaven National Laboratory. The fifth and sixth quarks were sometimes called truth and beauty in the past, but even physicists thought that was too cute. The bottom quark was first discovered at Fermi National Lab (Fermilab) in 1977, in a composite particle called Upsilon ( ). The top quark was discovered last , also at Fermilab, in 1995. It is the most massive quark. It had been predicted for a long time but had never been observed successfully until then. Strangeness Strangeness Quarks are the building blocks of hadrons, such as protons and neutrons. The six types of quarks are up (u), down (d), strange (s), top (or truth, t), charm (c), and bottom (or beauty, b).

The first three are known as "light quarks", while the latter three are "heavy quarks." (See the chart for more information.) There are six quantities called quantum numbers that describe every elementary particle, and each type of quark has its own set of quantum numbers. Here are the quantum numbers of the light particles: Particle Spin Spin Hypercharge Strangeness Baryon Number Charge I I3 Y S B Q u 1/2 +1/2 +1/3 0 1/3 2/3 d 1/2 -1/2 +1/3 0 1/3 -1/3 s 0 0 -2/3 -1 1/3 -1/3 Strangeness is the name given to the fifth quantum number. It was postulated (discovered) in 1953, by M. Gell-Mann, T. Nakano and K. Nishijima, each working independently. The next year it was clearly demonstrated experimentally.

It is a property of subatomic particles, and only applies to those known as hadrons, which include protons, neutrons, pions, kaons, and lambda, omega, and rho particles, among others. The symbol for strangeness is S. The strangeness of a particle is the sum of the strangeness of its component quarks. Of the six flavors of quarks, only the strange quark has a nonzero strangeness. The strangeness of nucleons is zero, because they only contain up and down quarks and no strange (also called sideways) quarks. For more information see the chart The Standard Model of Fundamental Particles and Interactions . We can find the strangeness of a particle by using the law of conservation of strangeness. For example, in a reaction where a negatively-charged pion interacts with a proton, a neutral kaon and a neutral lambda particle are formed. Since the strange numbers of the pion and proton are both zero and the kaon has a strangeness of +1, we know that the lambda particle's strangeness is -1.

"It is found that strangeness is conserved in all processes mediated by the strong and electromagnetic interactions."(Beiser p.534) An example is the high-energy proton-proton collision (protons have S=0), which creates a kaon(S=1), a lambda hyperon (S=-1),a proton (S=0) and a positively-charged pion (S=0). "On the other hand, strangeness can change in an event governed by the weak interaction."(Beiser p.534) However, the violation of this strangeness can only be +/- 1. Therefore, a particle such as a negatively-charged hyperon (S=-2) can not decay directly into another particle with a strangeness that is different by 2 or more, such as a neutron (S=0). Such a decay must proceed via two steps: The negatively-charged hyperon (S=-2) decays into a lambda hyperon (S=-1) and a negatively-charged pion (S=0). The lambda hyperon then decays into a neutron (S=0) and a neutrl pion (S=0).

The hypercharge (Y) is defined as the sum of baryon number and strangeness. Because both of these quantities are conserved under the influence of the stong and the electromagnetic forces, the hypercharge, therefore, should also be conserved. Four of the five quantum numbers listed above can be related by the equation: Q=I3 + B/2 + S/2. Resources: Beiser, Arthur. _Concepts_of_Modern_Physics,_Fourth_Edition_. New York:McGraw-Hill Book Company,1987. Particle Physics 1) Identify the following types of decay, for six points each. a) An unstable nucleus ejects an energetic electron and an antineutrino, and a neutron becomes a proton. The atomic number of the resulting atom is one greater, while the mass number is the same. For example, hydrogen-3 decays to helium-3. Answer: electron emission or negative beta decay (prompt on just beta decay) b) An unstable nucleus ejects a particle consisting of two positive charges and four atomic mass units. The atomic number of the resulting atom is two less, while the mass number is four less.

For example, polonium-210 decays to lead-206. Answer: alpha decay c) An electron orbiting around the nucleus combines with a nuclear proton to produce a neutron and a neutrino, which is ejected. The atomic number of the resulting atom is one less, and the mass number remains the same. Answer: electron capture or K-capture (prompt on beta decay) d) Unstable nuclei resulting from either of the other major types of decay can dissipate excess energy by undergoing this additional type of decay. In one type, photons are radiated. In another type, called internal conversion, excess energy in a nucleus is transferred to one of its own orbiting electrons, which is ejected. In a third type, called internal pair production, excess energy is converted into an electron and a positron which are emitted together. Answer: gamma decay e) A proton decays into a neutron and ejects a positron and a neutrino. The atomic number of the resulting atom is one less, while the mass number is the same.

Answer: positron emission or positive beta decay (prompt on just beta decay) 2) Give the nation or, if it is in the United States, the state in which each of the following laboratories important in the development of particle physics is located, for three points each. For an additional 4.5 points each, also give the city. a) CERN - the European Laboratory for Particle Physics Answer: Geneva, Switzerland 3) FFPE, list the four fundamental forces in increasing order of strength. For an additional ten points, then give the ratio of the strength of the weakest to the strongest, within three orders of magnitude. Answer: gravity, weak nuclear, electromagnetic, strong nuclear; 10-39 (accept 10-36 to 10-42) 4) Given information about the substance and time of their work, as well as their nationality, identify the following people who have contributed to particle physics, FFPE.

a) English, 17th Century, formulated the law of universal gravitation Answer: Isaac Newton b) Danish, 1913, incorporated the ideas of quantization in his atomic model Answer: Niels Bohr c) Italian-American, 1934, incorporated the neutrino in his description of beta decay Answer: Enrico Fermi d) one American and one Israeli, 1962, proposed SU(3) symmetry for hadrons Answer: Murray Gell-Mann and Yural Ne'eman e) American, 1964-1965, introduced the idea of colour Answer: Oscar Greenberg 5) Given a subatomic particle and the year of its discovery or postulation, identify the discoverer or postulator, FFPE. Answer: weak nuclear and gravity c) The first two forces to be described by a single unified theory Answer: electromagnetic and weak nuclear 7) In this bonus, we will construct a hierarchical chart of all particles. Pencil and paper ready. Sixteen total answers will be required, worth 1.875 points each. a) All particles can be classified into one of two major categories.

The first consists of all particles of matter and is characterized by half-integral spins and obedience to the Pauli exclusion principle. The second consists of all particles which carry force and is characterized by whole-integral spins. Name these two categories, in the order described. Answer: fermions and bosons b) We will now expand the bosons category. Name, in order, the bosons associated with the electromagnetic, strong nuclear, gravitational, and weak nuclear forces. Note that the existence of the boson for gravity has not yet been experimentally verified, and that there are three bosons associated with the weak nuclear force - all or nothing. Answer: photon, gluon, graviton, W+ / W- / Z c) We will now expand the fermions category. All fermions can be classified into one of two major categories. The first consists of particles composed of quarks and which are affected by the strong nuclear force. The second consists of particles which do not seem to be further divisible and are not affected by the strong nuclear force. Name these two categories, in the order described. Answer: hadrons and leptons d) We will now expand the leptons category.

There are six types of leptons, three charged and three uncharged, each of which has a corresponding antilepton. Name the six leptons. Answer: electron, muon, tau, electron neutrino, muon neutrino, tau neutrino e) We will now expand the hadrons category. All hadrons can be classified into one of two major categories. The first consists of particles made of three quarks, such as the proton and neutron. The second consists of particles made of a quark and an antiquark, such as pions and kaons. Name these two categories, in the order described. Answer: baryons and mesons f) All hadrons are composed of quarks. But that is the subject of another bonus. 8) Given information about the substance and time of their work, as well as their nationality, identify the following people who have contributed to particle physics, FFPE.

a) French, 18th Century, formulated a law of electrostatic force similar to the law of universal gravitation Answer: Charles Coulomb b) two Americans, 1964, introduced the idea of quarks Answers: Murray Gell-Mann and George Zweig c) two Americans and one English, 1979, won Nobel Prize for their work in developing electroweak theory, introducing massive bosons and using SU(2) * U(1) symmetry Answer: Sheldon Glashow, Abdus Salam, Steven Weinberg 9) Answer the following concerning quarks. a) For two points each, name the six flavours of quarks. Answer: up, down, strange, charm, bottom (or beauty), top (or truth) (in any order) b) For three points each, now arrange them in increasing order of mass. Answer: up, down, strange, charm, bottom (or beauty), top (or truth) (in that order) 10) Given its component quarks, identify the hadron, FFPE.

f) up and antiup or down and antidown Answer: neutral pion (prompt on just pion) 11) Identify the following attempts at comprehensive theories in particle physics, FTPE. a) Our current understanding combines electroweak theory and quantum chromodynamics. It divides matter into quarks and leptons, and describes the four known types of interactions among them. No experimental results actually conflict with this theory, although it has a large number of unsatisfactory features which raise a number of questions. Answer: Standard Model b) Most examples of this type of theory are based on the mathematical symmetry group SU(5) and suggest that quarks and leptons can be interconverted through new X gauge bosons. They are inspired by evidence that the strong force is weaker at shorter distances, suggesting that the strengths of three of the fundamental forces may become the same at high energies. They seek to unify the strong nuclear force with electroweak theory. Answer: GUTs (grand unified theories) c) This type of theory, the dream of theoretical physicists, would unify all four fundamental forces, including gravity.

Answer: TOE (theory of everything) 12) Given information about the substance and time of their work, as well as their nationality, identify the following people who have contributed to particle physics, FFPE.

a) Scottish, 1850s, described the relations of electric and magnetic fields to the forces that produce them in a set of four basic equations, including Gauss's, Ampere's, and Faraday's equations Answer: James Maxwell b) French, 1896, discovered radioactivity Answer: Henri Becquerel c) German, early 1900s, theorized that electromagnetic radiation, such as light, occurs in discrete bundles, or "quanta," of energy known as photons Answer: Max Planck d) German, 1927 and 1932, proposed his uncertainty principle and proposed that neutrons and protons are the same type of particle, held together by electron exchange particles Answer: Werner Heisenberg e) English, 1927 and 1928, proposed the first quantum field theory for electromagnetism, and put forth the relativistic electron theory, which predicted the existence of positrons Answer: PAM Dirac f) Swedish, 1930s, proposed a weak force carrier with a spin of one; probably not the namesake of a Houston-area high school which has produced such celebrities as Grant Gavranovic, Suzy Rivo

ire, and Matt Sokol Answer: Oskar Klein 13) One of the most popular theories of everything currently under consideration brings together two ideas which originated in the 1970s.

Identify the following about this theory, FTPE. a) One of the two ideas was that, in order for the strengths of the strong, weak, and electromagnetic interactions to converge properly, this type of symmetry must be included. It is the symmetry between fermions and the gauge bosons that mediate their interactions, and it predicts that every known particle should have a partner with a different spin. Answer: supersymmetry b) The second idea was to regard all particles, including quarks, leptons, and bosons, not as points in space, as in conventional field theories, but as extended one-dimensional objects known as these. Answer: strings c) The combined theory, known by this name and developed in the mid-1980s, predicts the existence of gravitons, and is entirely self-consistent. Answer: superstring theory 14) Answer the following about particle physics terms which are related to College Bowl players, except those from Texas A&M of course, for ten points each. a) In 1947, it was found that particles 800 times more massive than electrons were created in strong interactions within cosmic rays and lived for a relatively long time without themselves interacting strongly with matter.

This behavior was explained by the introduction of this property, which is conserved in strong nuclear reactions, and all particles were assigned a quantum number for this property. The pion, proton, and neutron have a value of zero for this number, but, if they were subatomic particles, most College Bowl players would have large integral values. Answer: strangeness b) These hypothetical particles could only interact with matter through the gravitational and weak nuclear forces. They are a possible explanation for the dark matter, so they would have to be very massive, but they must also interact very weakly with matter, or else they would already have been discovered. Some, however, might say that they already can be easily found on most College Bowl teams. Answer: WIMPs (weakly interacting massive particles) c) Academic Decathletes may remember from 1997 SuperQuiz that the term quark comes from this James Joyce novel. Answer: Finnegans Wake 15) Given information about the substance and time of their work, as well as their nationality, identify the following people who have contributed to particle physics, FFPE.

a) one American and one Japanese, 1953, proposed strangeness property Answer: Murray Gell-Mann and Nishijima Kazuhiko b) two Americans, 1958, proposed vector minus axial vector theory, providing the mathematical structure of weak interactions and incorporating parity violations Answer: Richard Feynman and Murray Gell-Mann c) one English and one American, 1980s, developed superstring theory Answer: Michael Green and John Schwartz 16) Given information about the substance and time of their work, as well as their nationality, identify the following people who have contributed to particle physics, FFPE.

a) English, 1938, proposed the idea of isotopic spin Answer: Nicolas Kenmer b) English, 1964, proposed hidden symmetry, a mechanism for "breaking" symmetry in electroweak theory Answer: Peter Higgs c) two Americans and one Japanese, 1965, renormalized quantum electrodynamics to eliminate embarrassing infinities Answer: Richard Feynman, Julian Schwinger, Tomonaga Shin'ichiro d) Dutch, 1971, proved that the Higgs mechanism could be renormalized Answer: Gerard 't Hooft Toss-Ups 1) When Einstein's special theory of relativity was introduced into quantum mechanics in order to describe the behavior of an electron in an electromagnetic field, physicists were surprised to find that the equations yielded two solutions for the allowable energies of an electron, one negative and one positive. In 1932, a particle was discovered which resolved this mystery. FTP, identify this particle, which has the same mass and spin as an electron but the opposite electric charge.

Answer: positron 2) Although this class of subatomic particle contains over 200 known members, most exist for less than 10-23 seconds, and only one is known to be stable. Its name comes from the Greek for "strong" because these particles experience the strong nuclear force. FTP, identify this group, whose members are built from quarks, and whose best known examples include the neutron and proton. Answer: hadrons 3) Those for each of the four fundamental forces all exhibit gauge symmetry, meaning that certain changes can be made that do not affect their basic structure, and that the relevant physical laws are the same in different regions of space and time. Since the 1930s, physicists have recognized that they can use these to model all four fundamental forces. Mathematically, they describe something that varies continuously through space and time. FTP, identify these constructs, which map the way force varies in strength and direction, and whose strength for magnets can be calculated using the Biot-Savart Law.

Answer: fields 4) The enormous energy of cosmic rays converts into matter according to the E=mc2 equation, producing pairs of positrons and electrons, which exist until they come close enough to each other to be converted back into energy. Atoms can exist only because there is an excess of electrons and protons in the everyday world, with no corresponding positrons and antiprotons FTP, identify this term for the act of mutual destruction in which a particle and its antiparticle are converted into energy. Answer: annihilation 5) Unlike quarks and leptons, they have integral spin quantum numbers. They act as a private, invisible messenger between particles, influencing their behavior with the information they convey, rather as a ball influences the action of children playing catch. FTP, identify this type of subatomic particle which, in a sense, carries force. Answer: gauge bosons (prompt on just bosons) 6) It has never been directly observed, so all of its assumed properties are based solely on the theory of general relativity. It must have a spin quantum number of two, and it must have no mass, only energy. FTP, identify this gauge boson, the hypothetical force carrier for gravity.

Answer: graviton 7) When a neutron transmutes into a proton, this gauge boson, one of the four described by electroweak theory, is emitted. In this case, the boson is virtual because, at 80.33 GeV, it is much more massive than the neutron, so its existence must be fleetingly short. FTP, identify this particle, which immediately transforms into an electron and an antineutrino, whose name is given by its charge and a letter of the alphabet. Answer: W- gauge boson (prompt on just W) 8) At the instant one particle emits a photon and another particle absorbs it, energy is not conserved. A discrepancy in energy may exist for a short time provided that the product of delta E and delta t is less than the value of Planck's constant divided by two pi. These photons, which effective "borrow" energy, are known as virtual photons. This temporary violation of energy and momentum conservation is allowable under the conditions of, FTP, what theory, proposed in 1927, which states that it is impossible, even in principle, to know all the details, such as position and momentum, about a particular quantum system.

Answer: Heisenberg's Uncertainty Principle 9) In 1938, it was realized that the strong force recognizes no difference between protons and neutrons. To model this symmetry, protons and neutrons can be seen as different states of a single basic nucleon, differentiated by an internal property with a value of plus or minus one-half. FTP, identify this property, analogous to the property which distinguishes two electrons in the same orbital. Answer: isospin (or isotopic spin; prompt on just spin although you really shouldn't) 10) It contains subgroups of objects that are related to each other by symmetric transformations, rather as a group describing the rotations of a square through ninety degrees contains the four symmetric positions of the square. Hadrons are naturally grouped in sets of eights or tens in a manner consistent with this type of symmetry, a fact recognized in 1962. FTP, identify this mathematical symmetry, often abbreviated as SU(3). Answer: special unitary group in three dimensions (accept rough equivalents and early SU(3)) 11) Physicists long assumed that this operation would make no difference to the laws of physics.

However, in 1956 Chinese-Americans physicists Tsung-Dao Lee and Chen Ning Yang discovered that the decay of strange particles could only be understood if the weak force violated this operation, a fact that was later experimentally confirmed. FTP, identify this operation which negates the values of a point's x, y, and z coordinates, much like reflecting something in a mirror, and in a different context, has served as a source of complaint for many NFL fans dissatisfied with the inability of any team to form a dynasty reminiscent of the '70s Steelers or '80s 49ers in recent years. Answer: parity 12) The existence of these particles is predicted by a theory of the same name which breaks symmetry. According to the mechanism, it is as if the universe lies at the bottom of a wine bottle. The symmetry of the bottle's base is clear from the top of the dimple in the center, but it is hidden from any point in the valley surrounding the central dimple. These particles would carry the additional fields needed for the symmetry breaking, have zero spin because they exist in a scalar field, and have higher energy when the field is zero than when it is nonzero.

FTP, identify these carrier particles which can endow mass on elementary particles through its interactions with them, and are Chris Romero's favorite type of subatomic particle. Answer: Higgs bosons 13) According to this theory, developed in the 1970s, quarks are bound together by exchanging gauge bosons and carry a property called colour. FTP, identify this theory which describes the strong nuclear force, and, except that it is based on a three-charge system of red, green, and blue rather than the two-charge system of positive and negative, is analogous to the theory describing the electromagnetic force, known as quantum electrodynamics. Answer: quantum chromodynamics 14) Like photons, they are massless and have a spin quantum number of one. However, unlike photons, they can interact with each other, which limits the range of their effectiveness. They carry charge in the form of a colour and an anticolour. FTP, identify this type of gauge boson, the exchange particle for the strong nuclear force, named for its ability to "glue" quarks together.

Answer: gluons 15) It decays after an average lifetime of 2.2 microseconds into an electron, a neutrino, and an antineutrino via the weak nuclear force. It has a mass of 106 MeV, 200 times greater than that of an electron but 17 times less than that of a tau. FTP, identify this subatomic particle, one of the three principle types of charged leptons. Answer: muon 16) Massive neutrinos, supersymmetric particles, and matter that has failed to ignite as stars are all possible explanations for it, although most theories favor more exotic explanations, introducing new kinds of particles. It has not been observed through radiation of any kind, but it must exist if the motions of stars and galaxies are to be understood. FTP, identify this type of nonluminous matter, believed to constitute more than ninety percent of the universe. Answer: dark matter 17) These hadrons decay via the strong force in the amount of time it takes light to cross the particle.

By colliding particles with a net energy that is just sufficient to create the rest mass of the new particle, the system absorbs more energy than usual because the energy is being supplied at the system's own natural frequency, and the particle can therefore be observed. FTP, identify this type of subatomic particle, named for the phenomenon by which they are observed, analogous to the theory which describes the stability of many chemical compounds, such as benzene. Answer: resonances 18) As it stood in the 1930s, quantum electrodynamics gave the wrong answers for quite simple problems. It said that the emission and reabsorption of the same photon would occur with an infinite probability, which led to infinities occurring in many situations. It even predicted that the mass of a single electron was infinite. In the late 1940s, a group of physicists ridded the theory of its embarrassing infinities by acknowledging all possible infinities and allowing the positive infinites to cancel the negative ones. FTP, identify this process, which transformed QED from a problematic theory to the most accurate quantum field theory scientists now have a their disposal.

Answer: renormalization 19) Its existence was first proposed in Japan, and it was discovered in 1937 in cosmic rays. Consisting of a quark and an antiquark, it can decay into a penetrating muon. Its mass is 200 times that of an electron, and it is chiefly responsible for the strong interactions between protons and neutrons in atomic nuclei. FTP, identify this particle, the lightest meson. Answer: pion (or pi meson) 20) When divided by two pi, it is known as Dirac's constant, and is used to calculate pure numbers, a unitless quantity used to compare the strengths of the fundamental forces. It is often defined as the elementary quantum of action, since its dimension is the product of energy and time. FTP, identify this constant which relates frequency to energy and has a value of 6.62*10-34 joule-seconds.

Quarks and Antiquarks Quarks and Antiquarks An overview of quarks and antiquarks including solutions to the questions on hadrons from the Egglescliffe Physics Website Particles Main HadronPhysics Introduction to Quarks Quarks are the elementary constituents from which Hadrons (baryons and mesons) are made. There are three main types (or flavors) of quark known as Up, Down and Strange. Each type of quark has different properties of mass, charge, baryon number and strangeness as shown in the table below. 1/3 -1 There are also three other much more massive quarks: Charm, Top and Bottom (sometimes called Truth and Beauty) but these are much rarer and the Top/Truth quark was only discovered in 1997. Quarks also have a corresponding antiquark which has similar properties but opposite and equal charge. Antiquarks have the same symbol as the quark but with an underline i.e. an antidown has the symbol d. Any particle containing quarks is termed a Hadron , however quarks do not ever exist on their own but bound into quark-antiquark pairs or triplets by the strong force . This is known as quark confinement.

In a triplet there will be three quarks (q q q) or three antiquarks (qqq ) but never a mixture, for example a proton consists of two up quarks and a down quark, these are called Baryons. In a pair there will always be one quark and one antiquark (q q )but never two quarks or two antiquarks, an example of this is the Pion, these are caled Mesons. . The following table shows the quark configuration and properties of some common Hadrons (These are the ones relevant to the AQA A-Level syllabus 2001) RHS has B = 1 + 0 + 0 = 1 Therefore baryon number is conserved Lepton number: RHS has L = 0 + (+1) + (-1) = 0 Therefore lepton number is conserved 5) The particle tracks are due to a magnetic field perpendicular to the plane of the particle motion. In accordance with the left hand rule this causes the +ve particles (e+) to curve anticlockwise and so generally be on the right of the bubble chamber.

However -ve particles (e-, W- and p- ) rotate clockwise and so tend to be on the right of the bubble chamber. A particle with no charge ( p, K0, X0 and L0 ) will have a straight path and will leave no visible track. The more massive the particle ( p = BqR) the larger the initial radius of the curve, so low mass charged particles will form a tightly wound spiral. Charge, lepton number and baryon number are conserved for all the events, here are two examples: After: 0 + 0 = 0 Therefore Q, B and L are conserved. 7) This is likely to be a strong interaction because Q,B,L and S are all conserved. 8) This is a weak interaction as strangeness changes by +1 in each decay. Remember strangeness only changes in weak interactions and is conserved in strong and electromagnetic interactions.

10) Time for light to cross an atom: Diameter of atom: approx 10-9 m Speed of light: approx 3x108 ms-1 Therfore time taken to cross atom = 10-17 s The lifespan of a L0 hyperon is about 10-10. From above it can be seen that light can cross an atom 10 million times in the lifetime of a L0 hyperon. So in some respects it lives quite a long time. Elementary particle resonances may be as short lived as 10-23 seconds ! Distance = 0.5 x 3x108 x 1.2x10-10 = 0.018 m 12) These energies have been calculated using relativistic mechanics. See Eg: Relativity Problems 2 . Click here to see the relativistic formula for kinetic energy. Speed /c Flavour - definition of flavour by The Free Dictionary Flavour - definition of flavour by The Free Dictionary Related to flavour: Natural flavour fla·vour 1. taste perceived in food or liquid in the mouth 2.

(Cookery) a substance added to food, etc, to impart a specific taste 3. a distinctive quality or atmosphere; suggestion: a poem with a Shakespearean flavour. 4. a type or variety: various flavours of graphical interface. 5. (General Physics) physics a property of quarks that enables them to be differentiated into six types: up, down, strange, charm, bottom (or beauty), and top (or truth) 6. flavour of the month a person or thing that is the most popular at a certain time vb (tr) to impart a flavour, taste, or quality to [C14: from Old French flaour, from Late Latin flātor (unattested) bad smell, breath, from Latin flāre to blow] ˈflavourer, ˈflavorer n 1. taste, esp. the distinctive taste of something as it is experienced in the mouth. 2. a substance or extract that provides a particular taste; flavoring. 3. the characteristic quality of a thing: to capture the flavor of an experience. 4. a particular quality noticeable in a thing: language with a strong nautical flavor. 5. Physics. a.

a property that distinguishes among the six kinds of quark: up, down, strange, charmed, bottom, and top. b. a property that distinguishes among the three kinds of lepton: electron, muon, and tauon. 6. Archaic. smell; odor; aroma. v.t. 7. to give flavor to (something). [1300–50; Middle English < Middle French fla(o)ur < Vulgar Latin *flātor stench, alter. of Latin flātus blowing, breathing; see flatus ] fla′vor•ful, fla′vor•some, adj. fla′vor•ful•ly, adv. fla′vor•less, adj. I will have been flavouring you will have been flavouring he/she/it will have been flavouring we will have been flavouring you will have been flavouring they will have been flavouring Past Perfect Continuous Noun 1.

flavour - the general atmosphere of a place or situation and the effect that it has on people; "the feel of the city excited him"; "a clergyman improved the tone of the meeting"; "it had the smell of treason" flavor , feel , spirit , smell , feeling , look , tone ambiance , ambience , atmosphere - a particular environment or surrounding influence; "there was an atmosphere of excitement" Hollywood - a flashy vulgar tone or atmosphere believed to be characteristic of the American film industry; "some people in publishing think of theirs as a glamorous medium so they copy the glitter of Hollywood" Zeitgeist - the spirit of the time; the spirit characteristic of an age or generation 2. kind , sort , form , variety - a category of things distinguished by some common characteristic or quality; "sculpture is a form of art"; "what kinds of desserts are there?" charm - (physics) one of the six flavors of quark strangeness - (physics) one of the six flavors of quark high energy physics , high-energy physics , particle physics - the branch of physics that studies subatomic particles and their interactions 3.

sapidity , savor , savour , smack , flavor , nip , relish , tang gustatory perception , gustatory sensation , taste , taste perception , taste sensation - the sensation that results when taste buds in the tongue and throat convey information about the chemical composition of a soluble stimulus; "the candy left him with a bad taste"; "the melon had a delicious taste" lemon - a distinctive tart flavor characteristic of lemons vanilla - a distinctive fragrant flavor characteristic of vanilla beans Verb cookery , cooking , preparation - the act of preparing something (as food) by the application of heat; "cooking can be a great art"; "people are needed who have experience in cookery"; "he left the preparation of meals to his wife" sauce - dress (food) with a relish curry - season with a mixture of spices; typical of Indian cooking resinate - impregnate with resin to give a special flavor to; "Greek wines are often resinated" savour , savor - give taste to salt - add salt to flavour noun 2.

quality , feeling , feel , style , property , touch , character , aspect , tone , suggestion , stamp , essence , tinge , soupçon (French) clothes with a nostalgic Forties flavour verb flavour of the month the latest thing , fashionable , in vogue , all the rage , the craze, du jour (French), the in thing (informal), culty , the new Hats were very much flavour of the month. Translations طَعْممَذاق ،نَكْهَه نَكْهَة يُعْطي نَكْهَةً chuťochutitatmosféra tat tat vermek hava lezzet lezzetlendirmek mùi vị flavour flavor (US) [ˈfleɪvəʳ] A. N (gen) → sabor m, gusto m (of a) (= flavouring) → condimento m (fig) → sabor m, aire m with a banana flavour → con sabor or gusto a plátano the decor has a Victorian flavour → la decoración tiene un sabor or aire victoriano B.

VT (Culin) → condimentar , sazonar (with con) the pudding is flavoured with liqueur → el postre tiene licor flavour (= taste) → goût m This cheese has a very strong flavour → Ce fromage a un goût très fort.

to give flavour to sth, to add flavour to sth → donner du goût à qch, relever qch flavour of the month [ice cream] → parfum m music with an African flavour → une musique avec une atmosphère africaine vt (with lemon, vanilla, herbs, spices) → parfumer flavour , (US) flavor n (= taste) → Geschmack m; (= flavouring) → Aroma nt; (fig) → Beigeschmack m; strawberry-flavour ice cream → Eis nt → mit Erdbeergeschmack; with a lemon flavour → mit Zitronengeschmack; 20 different flavours → 20 verschiedene Geschmackssorten; the film gives the flavour of Paris in the twenties → der Film vermittelt die Atmosphäre des Paris der zwanziger Jahre or Zwanzigerjahre ; he/it is flavour of the month (inf) → er/es ist diesen Monat in (inf) vt → Geschmack verleihen (+dat) → or geben (+dat); pineapple-flavoured → mit Ananasgeschmack flavour 1.

n → sapore m, gusto ; (of ice-cream) → gusto ; (flavouring) → aroma m (fig) → atmosfera 2. vt to flavour (with) (Culin) (cake) → aromatizzare (con); (savoury dish) → condire (con), insaporire (con) vanilla-flavoured → al gusto di vaniglia flavour noun (American) flavor (ˈfleivə) 1. taste. The tea has a wonderful flavour.

smaak; geur طَعْم вкус sabor chuť der Geschmack smag γεύση sabor maitse طعم maku saveur טעם स्वाद okus íz rasa bragð, keimur sapore 味 풍미 skonis garša; aromāts rasa smaak smak , aroma , bouquet smak مزه sabor aromă, savoare аромат chuť okus ukus smak รสชาติ tat , lezzet 味道，香味 смак; присмак ذائقہ vị ngon; mùi thơm; mùi vị 味道，香味 2. atmosphere; quality. an Eastern flavour.

geur مَذاق ،نَكْهَه привкус ar atmosféra der Beigeschmack islæt; præg γεύση , ατμόσφαιρα atmósfera hõng ویژگی؛ حال و هوا tuntu atmosphère אווירה पुट atmosfera, ton légkör suasana andblær atmosfera 趣 정취, 풍취 atmosfera, kvapas nokrāsa suasana karakter atmosfære atmosfera اتموسفير، دمځكې ګرد چاپېره فضا، فضا ( لكه دصيميت فضا )، دبحر په سطحه كې دهوا دفشار واحد traço at­mo­sferă атмосфера atmosféra ozračje atmosfera doft, prägel บรรยากาศ özellik , hava 風味 колорит; особливість ماحول، خوبی hương vị 风味 verb to give flavour to. She flavoured the cake with lemon.

geur; gegeur يُعْطي نَكْهَةً овкусявам aromatizar ochutit würzen krydre; sætte smag på αρωματίζω sazonar , condimentar maitsestama چاشنی زدن به maustaa parfumer לְתַבֵּל खास स्वाद बनाना začiniti (meg)ízesít memberi rasa bragðbæta aromatizzare , insaporire 味を付ける 맛을 들이다 (pa)gardinti, ádëti kokio prieskoni pielikt garšvielas memberi perasa op smaak brengen krydre , smake til przyprawić چاشنی خورل aromatizar a aromatiza приправлять ochutiť začiniti začiniti smaksätta แต่งรส tat vermek, lezzetlendirmek 將...調味 надавати смаку ذائقہ دینا cho gia vị; thêm

 gia vị 给...调味 ˈflavouring , (American) flavoring noun anything used to give a particular taste.

lemon flavouring.

geursel نَكْهَه подравка aroma příchuť, koření die Würze smagsstof αρωματική ουσία condimento , esencia maitseaine چاشنی mauste parfum תבלין स्वादिष्ट बनाने के लिये मिलाया गया पदार्थ začin, primjesa ízesítés penyedap makanan bragðefni, krydd aroma 調味料 독특한 맛 prieskonis garšviela perasa smaakstof krydder , smaksstoff przyprawa چاشنی aroma aromă ароматическое вещество príchuť začimba, dišava začin smaksättning เครื่องปรุงรส tat verici şey 調味品 приправа; ароматизатор کوئی خاص ذائقہ لانے کے لۓ استعمال کی گئی شے đồ gia vị; hương

 liệu 调味品 flavour

Question: What type of particle has 'flavours' known as top (or truth), bottom (or beauty), up, down, strange and charm?
Answer: QUARK